Turkish authorities said its strikes hit locations of the PKK rebels. However, Kurdish sources in northern Iraq reported that Friday’s strikes also caused civilian casualties.

This comes amid continues siege imposed by Turkish military and security forces on the southeastern town of Cizre under the pretext that PKK holds positions inside the town.

Dozens of people have been killed during a Turkish military operation in Cizre since a curfew was enforced on the town a week ago.

On Thursday, the pro-Kurdish People’s Democratic Party (HDP) said in a statement that 21 civilians have died over a week of Turkish curfew.

Selahattin Demirtas, the co-chairman of the HDP, has been leading fellow deputies and dozens of supporters on a march to Cizre to end the curfew and draw attention to the plight of its 120,000 residents.

Turkey started airstrikes on PKK positions in July, killing more than 900 Kurdish rebels. This coincided with a fierce response by the PKK whose attacks have killed some 100 Turkish forces in two months.

The ongoing clashes have shattered a peace process begun by President Tayyip Erdogan in 2012 to end a conflict that has killed at least 40,000 people over three decades.